Brian Fung spotted an interesting pattern in a new national Pew Research survey out this week looking at how Americans perceive the future of technology. As part of the survey, Pew asked 1,001 adults this open-ended question: "If there was one futuristic invention that you could own, what would it be?"

About 9 percent of the respondents went with some kind of cure for diseases (which was maybe not a direct answer to the actual question). But here are some of the next most popular answers: time machines, flying cars and flying bikes, personal space craft, self-driving cars, and teleporters. In short, people are looking for fantastical solutions to the otherwise mundane problem of getting around. When we try to envision how technology might significantly improve our lives, a lot of us are thinking about transportation.

Of all of those inventions, autonomous cars are the closest to reality. Google is already piloting prototypes on California highways. And the federal government is already planning regulation for "vehicle to vehicle" communication technology, a feature that will be essential to autonomous cars as they ping signals back and forth to each other and to the infrastructure around them (in the absence of human command). There are a lot of logistics and technical details that will still take years to work out, but the ubiquitous autonomous car is a lot closer than the time machine.

When that future does arrive, Pew's survey broaches a fascinating question about how we'll relate to these things. Nearly half of the people Pew surveyed said they would like to give driverless cars a try. That's way more than are willing to try, say, meat grown in a lab. An even larger share (59 percent) of college graduates are on board. Meanwhile, urban (52 percent) and suburban residents (51 percent) are much more intrigued than people who live in rural America (36 percent).

But on top of the people who'd like to go for a ride in a driverless car, 3 percent volunteered that they would specifically like to own one when pondering all of the theoretical inventions out there. (For comparison's sake, 2 percent said that they'd like to get their hands on a technological advance that could create world peace or stop wars). And this is interesting because autonomous vehicle technology has the potential to dramatically change our relationship not just to cars, but to car ownership.

Transportation geeks generally love the idea of autonomous cars because they'll make ownership unnecessary. When cars no longer need people to drive them, they can drive around all day, transporting one passenger after another after another -- in a network that might look a lot like personalized public transit. The resulting transportation system would be tremendously efficient. Cars wouldn't spend the vast majority of their lives parked. We wouldn't need to devote so much of our land to parking spots. We could get rid of the urban congestion that's caused purely by people driving around looking for parking. (Think about it: last time you planned a trip downtown, you factored in 10 minutes or more to "find time for parking," right?)

An owned asset that's generally used for only a small fraction of the day could instead be communally deployed 24 hours a day. You wouldn't need to own your own, because the closest autonomous car would simply pull up to your doorstep when you needed it -- no more trying to remember where you parked it last.

And yet: We don't own cars today purely for mobility. Many of us also own cars because, well, we like them. They're status symbols. They're intensely personal and mobile private spaces. We slap bumper stickers on the rear and hang graduation tassels from the mirror because cars are an extension of and platform for our identities (have I mentioned that I'm the kind of person who owns a Prius!). Cars come in so many makes and models not just because some people need pick-up trucks and others mini-vans, but because a certain kind of person wants an Audi A3 and another a Chevy Trailblazer.

Maybe you own a car because you need it, for mobility. But you own thatcar because you want it for some more intangible reason.

In the future, however, the arrival of mass-market autonomous cars will force us to confront the difference between these two ideas. When you no longer need to own a car for mobility, will you still want one anyway for the love of cars, or for what they say about you, or for some other deeply personal reason? A lot of us may not even know the answer to this question until that moment comes.

It seems likely, though, that some people won't want to give up private cars, just as some drivers don't want to give up control over driving to a computer. High-end car-makers like Mercedes are already wrestling with this. Burkhard Bilger, who wrote an excellent piece on Google's autonomous car project in The New Yorker last November, touches on this:

Mercedes has a knottier problem. It has a reputation for fancy electronics and a long history of innovation. Its newest experimental car can maneuver in traffic, drive on surface streets, and track obstacles with cameras and radar much as Google’s do. But Mercedes builds cars for people who love to drive, and who pay a stiff premium for the privilege. Taking the steering wheel out of their hands would seem to defeat the purpose—as would sticking a laser turret on a sculpted chassis. “Apart from the reliability factor, which can easily become a nightmare, it is not nice to look at,” Ralf Herrtwich, Mercedes’s director of driver assistance and chassis systems, told me. “One of my designers said, ‘Ralf, if you ever suggest building such a thing on top of one of our cars, I’ll throw you out of this company.’ ”

The kind of person who owns a Mercedes may not happily give it up even if it becomes fully autonomous one day, even if there are 10 shared autonomous Mercedes in the neighborhood. For those of us who drive less luxury cars, the question will be even more interesting.